week 5 paired t-test

Vocabulary flashcards covering key concepts in psychological research methods.

Paired t-test

A parametric test used to determine whether the means of two related groups are statistically different from each other.

Inferential statistics

Statistical methods that allow us to infer conclusions about populations based on sample data.

Descriptive statistics

Statistics that summarize or describe the characteristics of a data set.

Null hypothesis (H0)

The hypothesis that there is no effect or no difference; it serves as a default position until evidence suggests otherwise.

Experimental hypothesis (H1)

The hypothesis that there is a difference or effect; it is what researchers aim to support through their data.

Type I error

The incorrect rejection of a true null hypothesis; a false positive.

Type II error

The failure to reject a false null hypothesis; a false negative.

Probability (p)

A measure expressed as a proportion indicating the likelihood of a particular outcome or result.

Significance level (alpha)

A predetermined threshold (commonly set at 0.05) used to decide whether to reject the null hypothesis.

Wilcoxon signed-rank test

A non-parametric test used to compare two related samples, often used as an alternative to the paired t-test when data assumptions are not met.

Independent t-test

A parametric test used to compare the means of two independent groups.

Mann-Whitney U test

A non-parametric test used to compare differences between two independent groups.

ANOVA (Analysis of Variance)

A statistical method used to determine if there are any statistically significant differences between the means of three or more independent groups.

Cohen's d

A measure of effect size that indicates the standardized difference between two means.

Normal distribution

A probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence.

Parametric tests

Statistical tests that assume the underlying data follows a certain distribution, often normal.

Non-parametric tests

Statistical tests that do not assume a specific distribution and can be used with ordinal data.